JP2000279888A - Ultrasonic cleaner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the cleanliness of an object by cleaning the surface and side of the object simultaneously, to keep an apparatus simple and small, and to reduce the amount of a cleaning liquid. SOLUTION: In an apparatus, a pair of protruded parts 5d is formed on the vibrating surface 5c of a wave guide 5. The cross-sectional shape in the advance direction of ultrasonic vibration is an isosceles right triangle, and the outer wall surface 5f is inclined at 45 degrees with the vibrating surface 5c and the inner wall surface 5e. In this way, the ultrasonic vibration is reflected by the outer wall surface 5f to be deflected in the side 6b direction of a substrate 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic excitation device used for cleaning, for example, semiconductor wafers and glass substrates, and an ultrasonic cleaning device provided with the same.

[0002]

2. Description of the Related Art As a conventional ultrasonic cleaning device, for example,
There is one described in JP-A-6-461. Hereinafter, a conventional ultrasonic cleaning apparatus will be described with reference to FIGS.

FIG. 7 is a sectional view of a conventional ultrasonic cleaning apparatus viewed from the front, and FIG. 8 is a bottom view of the conventional ultrasonic cleaning apparatus shown in FIG.

As shown in FIG. 7, a conventional ultrasonic cleaning apparatus 130 includes a case 111 having a substantially concave cross section and a box shape formed in a longitudinal direction, and an ultrasonic vibrator disposed in a concave portion of the case 111. And an ultrasonic oscillator 1 for driving the ultrasonic transducer 115 with an ultrasonic signal of, for example, 950 kHz.
16. The case 111 is made of, for example, stainless steel.

[0005] The case 111 includes an upper case including the vibration plate 111a of the ultrasonic vibrator 115 disposed in the recess, and is provided to face the vibration plate 111a.
The angle θ (0 <θ <
10 °) and a lower case including a reflecting plate 111b provided at an angle.

The upper case and the lower case are fastened and fixed via a packing 119 by bolts 121 and nuts 122. And as shown in FIG.
On the side surface of the lower case, three cleaning liquid supply ports 11 are provided.
2, two overflow discharge ports 114 provided on the side surface opposite to the cleaning liquid supply port 112, and a cleaning liquid outlet section 12 formed in the center of the reflection plate 111b.
6 and a slit 125 formed at the center of the cleaning liquid outlet portion 126.

A rectifying plate 118 having a substantially L-shaped cross section is attached to one side of the packing 119. A plurality of slits 120 are formed in the lower part of the rectifying plate 118 and function as a member for rectifying.

Next, the operation of the ultrasonic cleaning apparatus 130 having the above configuration will be described.

As shown in FIG. 7, the cleaning liquid 124 is supplied from the cleaning liquid supply port 112 to the case 111 from the direction of arrow X.
The cleaning liquid 124 is supplied to the inside of the current plate 11.
The cleaning liquid is rectified by the slits 120, flows in the case 111 in a laminar flow, flows in a uniform shape along the cleaning liquid ejection port 113, and is ejected from the cleaning liquid ejection port 113 onto the object to be cleaned 117. At this time, the ultrasonic vibrator 115 is driven by a voltage of a predetermined frequency, and emits ultrasonic waves toward the reflecting plate 111b, which is the bottom surface of the case 111, via the vibrating plate 111a. Since the reflection plate 111b is inclined by a predetermined angle θ, the ultrasonic waves 123a and 123b reflected by the reflection plate 111b repeatedly converge on the cleaning liquid ejection port 113 while repeating reflection, and Sound wave deriving unit 1
26, the object 1 to be cleaned
17 is irradiated with a strong ultrasonic cleaning solution.

[0010]

As shown in FIG. 7, in the conventional ultrasonic cleaning apparatus 130, for example, the object 117 to be cleaned such as a semiconductor wafer or a glass substrate is transported by means of rollers or the like (not shown). Thus, for example, cleaning is performed by passing below the cleaning liquid jet port 113 at a constant speed in the direction of arrow Y.

That is, the conventional ultrasonic cleaning apparatus 13
Reference numeral 0 denotes a so-called single-wafer cleaning apparatus for cleaning the object to be cleaned 117 one by one.
The ultrasonic waves emitted from the slit 125 are focused and become strong.

However, since the conventional ultrasonic cleaning apparatus 130 has a configuration in which the cleaning liquid 124 is ejected from the slits 125, the irradiation area of the cleaning liquid 124 excited by ultrasonic waves on the object 117 to be cleaned is very small. It is narrow. For this reason, in order to obtain a sufficient cleaning effect, it is necessary to use a plurality of the ultrasonic cleaning devices 130 in parallel, which tends to be expensive, and the amount of the cleaning liquid 124 used is relatively large. It has become something.

The ultrasonic cleaning apparatus 130 is capable of cleaning the surface 117a of the object 117 to be cleaned which is directly irradiated with the cleaning liquid 124.
In the thickness direction, that is, in the direction parallel to the transport direction (arrow Y direction), the cleaning effect of the side surface 117b may not be sufficiently obtained. If a separate ultrasonic cleaning device is provided for the side surface 117b and the processing is performed, the side surface portion 11
Although the cleaning of 7b is possible, the whole apparatus becomes complicated and large, and causes high cost.

On the other hand, with the recent increase in the degree of integration of semiconductors, higher cleanliness is required for cleaning semiconductor wafers and the like. There is a need to maintain high cleanliness.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and it is possible to simultaneously clean a surface and a side surface of an object to be cleaned, thereby improving the cleanliness of the object to be cleaned, and further increasing the complexity of the apparatus. It is an object of the present invention to provide an ultrasonic cleaning apparatus capable of avoiding an increase in size and reducing the amount of cleaning liquid. It is another object of the present invention to provide an ultrasonic excitation device suitable for the ultrasonic cleaning device.

[0016]

According to the present invention, there is provided an ultrasonic excitation device comprising: a vibrator for generating ultrasonic vibration of about 200 kHz or more; and a waveguide coupled to the vibrator for guiding the ultrasonic vibration to an external load. An ultrasonic excitation device having a body, wherein the waveguide includes a projection integrally formed on an oscillation surface facing the surface having the vibrator, and the projection is provided on the oscillation surface side. An inner wall surface provided to face and perpendicular to the oscillation surface, and an outer wall surface deflecting the ultrasonic vibration toward the inner wall surface.

Further, the outer wall surface is a taper surface having an angle of 45 degrees with respect to the oscillation surface and the inner wall surface, respectively.

Further, the inner wall surface is an arc-shaped curved surface.

Further, the waveguide has a dimension in the traveling direction of the ultrasonic vibration that is an integral multiple of a half wavelength of the ultrasonic vibration based on the sound velocity of the material of the waveguide. When the acoustic impedances of the vibrator, the waveguide, and the external load are Rma ₁ , Rma _2, and Rma ₃ , respectively, they satisfy the following expression: Rma ₁ <Rma ₂ <Rma ₃ .

Further, the ultrasonic cleaning apparatus of the present invention includes a conveying means for conveying an object to be cleaned, a liquid supply means for supplying a cleaning fluid, and an ultrasonic excitation device for exciting the cleaning fluid. An ultrasonic cleaning device, wherein the ultrasonic excitation device includes:
A vibrator that generates ultrasonic vibration of about 200 kHz or more,
A waveguide that is coupled to the vibrator and guides the ultrasonic vibration to the cleaning fluid, wherein the waveguide is formed integrally with an oscillation surface opposed to a surface having the vibrator. Portion, the protrusion has an inner wall surface provided facing the oscillation surface side and perpendicular to the oscillation surface, and an outer wall surface deflecting the ultrasonic vibration toward the inner wall surface side. Things.

Further, the outer wall surface is a taper surface having an angle of 45 degrees with respect to the oscillation surface and the inner wall surface, respectively, and is approximately 3 degrees between the oscillation surface and the inner wall surface and the object to be cleaned. The liquid supply means supplies the cleaning fluid into the gap.

Further, the transfer device transfers the object to be cleaned along the inner wall surface.

Further, the inner wall surface is a curved surface having a radius of curvature of the object to be cleaned.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described with reference to the accompanying drawings.

First, an ultrasonic cleaning apparatus (including an ultrasonic excitation apparatus) as a first embodiment of the present invention will be described with reference to FIGS.

FIG. 1 is a perspective view showing an ultrasonic cleaning apparatus as a first embodiment of the present invention. FIG. 2 is a front view including a partial cross section of the ultrasonic cleaning apparatus shown in FIG. 1, and FIG. 3 is an enlarged front view of a part of the ultrasonic cleaning apparatus shown in FIG. FIG. 4 is a side view of the ultrasonic cleaning apparatus shown in FIGS.

As shown in FIG. 1, the ultrasonic cleaning device 20a
Is a liquid supply for supplying a cleaning fluid 15 such as pure water, an ultrasonic excitation device 1, a transport device 2 for transporting a substrate 6 as an object to be cleaned such as a semiconductor wafer or a glass substrate, for example. And a liquid supply device 3 as a means.

First, the ultrasonic excitation device 1 provided in the ultrasonic cleaning device 20a will be described.

As shown in FIGS. 2 and 4, the ultrasonic excitation device 1 is formed in a substantially rectangular parallelepiped waveguide 5 and in a rectangular plate shape. The oscillator 4 includes an oscillator 4 coupled with an adhesive or the like, and an oscillator (not shown) for applying a voltage having a predetermined driving frequency to the oscillator 4. Surface facing the surface having the element 4, that is, an oscillating surface 5c for oscillating ultrasonic waves
It is configured to be used with the lower side.

The vibrator 4 is a PZT (piezoel).
An electrode plate 4a and an electrode plate 4b are adhered to both surfaces of an element (electric: piezoelectric element), and a part of the electrode plate 4b on the lower surface side is folded back to the upper surface side in a non-contact state with the electrode plate 4a. The electrode portion 4c. The length and width of the vibrator 4 are the length L and width W of the waveguide 5.
(See FIGS. 2 and 4), and a pair of power transmissions for applying a voltage of a predetermined driving frequency from an oscillator (not shown) to predetermined positions of the electrode portion 4c and the electrode plate 4a. Each of the wires 8 is connected.

When a voltage of a predetermined drive frequency is applied to the vibrator 4 by an oscillator (not shown),
An ultrasonic vibration of this frequency is generated. The drive frequency is set to an extremely high value of about 200 kHz or more, and is 1 MHz in this embodiment.

The waveguide 5 resonates with the ultrasonic vibration generated by the vibrator 4 and transmits the ultrasonic vibration to a cleaning fluid 15 such as pure water supplied by the liquid supply device 3. Act as In the present embodiment, the waveguide 5 only transmits the ultrasonic vibration to the cleaning fluid 15 and does not have a function of mechanically amplifying it. May have an amplifying function.

The waveguide 5 is formed of duralumin or stainless steel (SUS) as a material, and has a substantially central portion in a thickness direction, that is, a traveling direction of the ultrasonic vibration generated from the vibrator 4. Has a flange portion 5a formed to protrude over the entire circumference.
The waveguide 5 in this embodiment uses duralumin as a more preferable example. As shown in FIGS. 2 and 4, the waveguide 5 has a thickness H from the surface having the vibrator 4, which is the upper surface, to the oscillation surface 5 c.
That is, the dimension from the upper surface to the oscillation surface 5c in the traveling direction of the ultrasonic vibration generated from the transducer 4 is calculated based on the material of the waveguide 5, that is, the sound speed of the duralumin in this case. The half-wavelength (λ /
The resonance length is set to substantially an integral multiple of 2), ideally just an integer multiple of 2).

Here, the half wavelength (λ / 2) is calculated as follows. λ / 2 = C / 2f where λ: 1 wavelength C: sound speed of duralumin = 5.15 × 10 ⁵ cm f: frequency = 10 ⁶ Hz Therefore, λ / 2 = 2.6 mm.

The thickness H of the waveguide 5 is set to 53 mm. That is, a half wavelength λ / 2 (about 2.6 m
m), and the thickness H is set to be large. Therefore, the waveguide 5 has a relatively large acoustic impedance, and the cleaning fluid 1 such as pure water supplied below the waveguide 5 as an external load.
Even if the cleaning fluid 1 does not exist below the oscillation surface 5c due to a shortage of 5 due to some cause, the vibration of the vibrator 4 is reduced due to the empty heating state, that is, the acoustic impedance of the entire apparatus is reduced. As it grows,
The generation of heat due to an increase in the effective output can be suppressed. Specifically, the acoustic impedance of the waveguide 5 is represented by the following formula: Rma ₁ <Rma ₂ <Rma ₃ (1) where Rma ₁ : acoustic impedance of the vibrator 4 Rma ₂ : acoustic of the waveguide 5 Impedance Rma ₃ : set to a state that satisfies the acoustic impedance of the cleaning fluid 15.

The function of suppressing the increase in the effective output is apparent from the following equation. Pa = Va ² / Rma (2) Rma = Rma ₁ + Rma ₂ + Rma ₃ (3) where Pa: effective output Va: applied voltage (constant) Rma: whole cleaning device (washing fluid 15 Acoustic impedance

That is, even if the cleaning fluid 15 decreases and the value of the acoustic impedance Rma ₃ becomes substantially zero, the waveguide 5 has the required magnitude of the acoustic impedance Rma _2. The output Pa is not greatly increased.

The value of the thickness H depends on the relationship with the acoustic impedance of the cleaning fluid 15 as an external load below the waveguide 5 and the magnitude of the transmitted ultrasonic energy. Can be arbitrarily changed. Incidentally, conventionally, in a high frequency band as in the present embodiment, ultrasonic energy is wasted, that is, a large amount of heat is generated, and for example, it is commonly recognized that the thickness is limited to two to three times the half wavelength. It had been.

In this embodiment, the waveguide 5 is made of duralumin, but the duralumin has a density (ρ) of about 2.8 g / cm ³ , which is lower than that of iron or stainless steel. It is about 1/3. In other words, it is a material with very little loss against high frequency ultrasonic vibration,
It is suitable as a material for the waveguide 5 in which the thickness H is set large. However, it can be applied as a waveguide, and it is of course possible to use any material having a density equal to or lower than that of duralumin, for example, using quartz, aluminum, an aluminum alloy, or the like. Is also good. If it is desired to increase the corrosion resistance of the waveguide material in accordance with the cleaning fluid to be used, for example, tantalum, titanium, or the like can be used.

As shown in FIGS. 2 and 4, the dimension of the waveguide 5 in a direction perpendicular to the traveling direction of ultrasonic vibration generated from the vibrator 4 (the direction of the thickness H). That is, in this embodiment, the length L and the width W are set to 136 mm and 40 mm, respectively, and are about 52 times and about 15 times the half wavelength λ / 2 (about 2.6 mm), respectively.
Although the length is doubled, the length L and the width W are variable according to the size of the object to be cleaned.

That is, if it is assumed that the length L and the width W use a relatively low frequency band, for example, about 20 kHz for the driving frequency of the vibrator 4, the waveguide 5 has a Poisson In order to suppress lateral vibration due to the influence of the (poisson) ratio, it is necessary to set the magnitude to λ / 3 or less. When it is desired to set the length L and the width W to be large, slits are formed at a pitch of λ / 3 or less, and small waveguides having a size of λ / 3 or less affect each other. It is necessary to take a form that is connected in a state where there is no connection. This is to prevent the vibration energy from being consumed by the waveguide itself due to the generation of the lateral vibration, and to give the pure water 1 clean vertical vibration without lateral vibration.

On the other hand, at an extremely high frequency of 200 kHz or more, for example, at a driving frequency of 1 MHz set in the present embodiment, it was found from the experiments conducted by the applicant that the adverse effect of the Poisson's ratio, ie, the occurrence of lateral vibration, was not generated. It has been confirmed that the length L and the width W of the waveguide 5 are:
Theoretically, it can be increased without limit. Therefore, the waveguide 5 does not need to form a slit, and the length L and the width W can be arbitrarily set to be λ / 3 or more.

The waveguide 5 has a pair of protrusions 5d on both sides of the oscillation surface 5c. The protrusion 5
d is such that the cross-sectional shape in the traveling direction of the ultrasonic vibration generated from the vibrator 4 is a right-angled isosceles triangle,
It is formed integrally with the waveguide 5. The protrusion 5d
The inner wall surface 5e facing the oscillation surface 5c is
c, and extends along the direction in which the object to be cleaned is transported by the transport device 2 described below.

That is, since the cross-sectional shape of the protrusion 5d in the traveling direction of the ultrasonic vibration is a right-angled isosceles triangle, the outer wall surface 5f of the protrusion 5d is in contact with the oscillation surface 5c and the inner wall surface 5e. Angle α (see Fig. 3)
Have 45 degree tapered surfaces.

The height H ₁ of the protruding portion 5d in the traveling direction of the ultrasonic vibration generated from the vibrator 4 is, for example,
It is set to 13 mm. That is, the half wavelength λ /
2 (about 2.6 mm), which is about five times the resonance length. The height H ₁ is a half wavelength (λ / 2) of the ultrasonic vibration calculated based on the sound velocity of the material of the waveguide 5.
If it is an integral multiple of the above, that is, the resonance length, it can be appropriately set according to the thickness of the substrate 6 as an object to be cleaned.

As shown in FIGS. 1, 2 and 4,
The flange 5a of the waveguide 5 has the waveguide 5
A pair of through holes 5b are formed along the longitudinal direction of the waveguide 5 as a means for cooling the waveguide 5. The through hole 5b
Nipple 7a is screwed into one end of
A nipple 7b is screwed into each of the other ends.

The nipple 7a is connected to two tubes 10a branched from a supply-side hose 9a, respectively, and as a cooling fluid in the through hole 5b through the hose 9a and the tube 10a. ,
For example, pure water is supplied. On the other hand, the nipple 7b has two tubes 1 branched from the discharge side hose 9b.
0b are connected respectively, and the tube 10b
The pure water as a cooling fluid is discharged through the hose 9b.

The cooling means composed of the through-holes 5b and the like is provided so that the waveguide 5 does not generate high heat but self-heats to some extent due to self-resonance. The heat which adversely affects the child 4 can be removed with high efficiency.

Next, the transfer device 2 provided in the ultrasonic cleaning device 20a of the present invention will be described.

The transfer device 2 as a means for transferring the article to be cleaned has a plurality of rollers 2a arranged at equal intervals and a drive means (not shown) for driving the rollers 2a. Then, for example, the substrate 6 as an object to be cleaned is placed on the plurality of rollers 2a, and the substrate 6 is transported at a predetermined speed in the arrow X direction.

Next, the liquid supply device 3 provided in the ultrasonic cleaning device 20a of the present invention will be described.

As shown in FIGS. 1 and 4, the liquid supply device 3 serving as a liquid supply means for the cleaning fluid 15 is provided for cleaning the pure water or the like from the side in which the substrate 6 to be cleaned advances. A liquid supply member 3a for supplying a fluid 15;
Suction member 3 for sucking air by the action of a pump (not shown)
b etc.

In this embodiment, the suction member 3b
The cleaning fluid 15 sucked by the above is cleaned by a filter (not shown) and returned to the liquid supply member 3a. That is, it is possible to significantly reduce the amount of the cleaning fluid 15 used. Although the effect of suppressing the usage amount of the cleaning fluid 15 is reduced, the cleaning fluid 15 sucked by the suction member 3b may be discarded as it is.
In addition to a, the liquid may be supplied from the suction member 3b side.

Next, the operation of the ultrasonic cleaning apparatus 20a as the first embodiment of the present invention will be described.

As shown in FIGS. 1 to 4, when a voltage having a predetermined drive frequency is applied to the vibrator 4 from the oscillator (not shown), the vibrator 4 is excited and Generates ultrasonic vibration. The generated ultrasonic vibration is transmitted to the cleaning fluid 15 supplied as an external load below the waveguide 5 through the waveguide 5.

The ultrasonic cleaning device 20a according to the present invention can be used as an object to be cleaned such as a glass substrate unless the cleaning fluid 15 such as pure water is supplied as an external load below the oscillation surface 5c. No ultrasonic vibration is transmitted to the substrate 6.

Therefore, as shown in FIG. 3, the gap d between the surface 6a of the substrate 6 and the oscillation surface 5c, the side surface 6b in the transport direction of the substrate 6, and the inner wall surface 5e of the protruding portion 5d. The gap e, that is, the separation distance is about 3 to 5
mm, and the substrate 6 is passed along the inner wall surface 5e by the rollers 2a of the transfer device 2 as transfer means in the transfer direction indicated by an arrow X (shown in FIGS. 1 and 4). The cleaning fluid 15 such as pure water is supplied from the liquid supply member 3a into the gap d and the gap e in the direction of the arrow Xa. At this time, the distance between the surface 6a of the substrate 6 and the oscillation surface 5c (gap d) and the substrate 6
Between the side surface 6b and the inner wall surface 5e of the protrusion 5d (gap e) by the action of surface tension.
5 is formed, and the ultrasonic vibration from the vibrator 4 is transmitted to the substrate 6 via the liquid film. Therefore, the ultrasonic cleaning device 20a is provided with the cleaning fluid 15
The substrate 6 can be cleaned by the action of the liquid film.

At this time, the ultrasonic vibration generated from the vibrator 4 is transmitted in a direction perpendicular to the oscillating surface 5c, and the oscillating surface 5c having the same width as the vibrator 4 vibrates uniformly over the entire surface. In addition, since the substrate 6 as the object to be cleaned is uniformly irradiated, the cleaning effect on the surface 6a of the substrate 6 is high.

As shown by a two-dot chain line arrow in FIG. 3, the ultrasonic vibration generated from the vibrator 4 is generated by the outer wall surface 5f of the protruding portion 5d on both sides of the oscillating surface 5c. The light is reflected toward the inner wall surface 5e, and travels in a direction perpendicular to the transport direction of the substrate 6 (the direction of the arrow X), that is, in the direction of the side surface 6b of the substrate 6.

That is, the cross-sectional shape of the protruding portion 5d in the traveling direction of the ultrasonic vibration is a right-angled isosceles triangle, and the outer wall surface 5f is formed by the oscillation surface 5c and the inner wall surface 5c.
e, the ultrasonic vibration from the vibrator 4 transmitted in a direction perpendicular to the oscillation surface 5c is reflected by the outer wall surface 5f. Then, it is deflected in the direction of the side surface 6b in the transport direction of the substrate 6 (the direction of the arrow X). Then, the cleaning fluid 15 in the form of a liquid film formed in the gap e is excited by the ultrasonic vibration transmitted from the inner wall surface 5e, and the side surface 6b of the substrate 6 can be cleaned. ing.

The ultrasonic cleaning device 20a has the following effects, for example.

That is, the oscillating surface 5c having the same width as the vibrator 4 vibrates uniformly over the entire surface, and the ultrasonic vibration from the vibrator 4 is uniformly applied to the substrate 6 as an object to be cleaned. Due to the irradiation, the cleaning effect on the surface 6a of the substrate 6 is high.

The waveguide 5 has the protruding portion 5d having a right isosceles triangular cross section in the traveling direction of the ultrasonic vibration, and the outer wall surface 5f of the protruding portion 5d is Since the taper surface has an angle of 45 degrees with respect to the inner wall surface 5e, it is possible to deflect the ultrasonic vibration from the vibrator 4 toward the side surface 6b of the substrate 6 by the outer wall surface 5f. The surface 6a and the side surface 6b of the substrate 6 can be cleaned at the same time, and the cleanliness of the substrate 6 as an object to be cleaned can be increased. In addition, since the protruding portion 5d has a simple configuration integrally formed with the waveguide 5, it is easy to form, and a high cleaning effect can be obtained at low cost.

If the cleaning fluid 15 having a liquid amount sufficient to generate a surface tension exists between the oscillation surface 5c and the inner wall surface 5e of the protruding portion 5d and the substrate 6 to be cleaned. For this reason, the usage amount of the cleaning fluid 15 can be significantly reduced.

The thickness H of the waveguide 5 is set to be large, and the waveguide 5 has a relatively large acoustic impedance. Therefore, even if the amount of the cleaning fluid 15 existing as an external load below the waveguide 5 is insufficient, the empty heating state, that is, the acoustic impedance of the entire apparatus is reduced, and the As the vibration increases, the effective output increases and heat generation can be suppressed. That is, it is possible to prevent the adhesive fixing the vibrator 4 to the waveguide 5 from deteriorating and peeling, and to prevent the vibrator 4 itself from cracking due to heat. I have.

Since it is not necessary to provide an interlock device including a sensor or the like for preventing empty heating, maintenance is extremely easy. And so on.

Next, an ultrasonic cleaning apparatus (including an ultrasonic excitation apparatus) as a second embodiment of the present invention will be described with reference to FIGS. However, portions having the same structure and function as those of the first embodiment are omitted because the description is duplicated, and only different points will be described. In FIGS. 5 and 6, parts having the same structure and function as those of the ultrasonic cleaning apparatus according to the first embodiment shown in FIGS. 1 to 4 are denoted by the same reference numerals.

FIG. 5 is a perspective view including a partially enlarged view showing an ultrasonic cleaning apparatus as a second embodiment of the present invention. FIG. 6 is a bottom view illustrating a state in which the ultrasonic cleaning apparatus illustrated in FIG. 5 cleans an object to be cleaned.

As shown in FIGS. 5 and 6, the second embodiment of the present invention
The ultrasonic cleaning apparatus 20b according to the embodiment corresponds to a disk-shaped object to be cleaned, for example, a substrate 6 such as a semiconductor wafer.

The ultrasonic excitation device 1 provided in the ultrasonic cleaning device 20b is arranged so that the ultrasonic vibrations generated from the vibrator 4 in the protruding portions 5d formed on both sides of the oscillation surface 5c of the waveguide 5 travel in the traveling direction. Has a trapezoidal shape, and the inner wall surface 5e has an arc shape along the circumferential direction of the substrate 6. In this embodiment, the inner wall surface 5e is a curved surface having the same radius of curvature as the substrate 6 as the object to be cleaned, and the ultrasonic excitation is performed in a state where the inner wall surface 5e forms a concentric circle with the substrate 6. The configuration is such that the device 1 is installed and used.

On the other hand, as in the first embodiment described above, the projecting portion 5d has an inner wall surface 5e facing the oscillation surface 5c side perpendicular to the oscillation surface 5c and an outer wall surface 5e.
f is a tapered surface having an angle α (see FIG. 5) of 45 degrees with respect to the oscillation surface 5c and the inner wall surface 5e.

The conveying device 2 as a means for conveying the object to be cleaned provided in the ultrasonic cleaning device 20b includes a plurality of rollers 2a arranged at equal intervals and a driving means (not shown) for driving the rollers 2a. And a table 2b on which the substrate 6 is placed, and the table 2b is moved in a direction (arrow Y direction) perpendicular to the oscillation surface 5c, and the table 2b is moved in the circumferential direction of the substrate 6. And a shaft 2c that freely rotates (in the direction of arrow Z).

Next, the operation of the ultrasonic cleaning apparatus 20b according to a second embodiment of the present invention will be described.

First, when the substrate 6 as an object to be cleaned is placed on the plurality of rollers 2a, the rollers 2a
Is driven by driving means (not shown), and the substrate 6
Is transported at a predetermined speed in the direction of arrow X, for example. And
The substrate 6 is pushed and placed on the table 2b by a pressing means (not shown).

The table 2b on which the substrate 6 is placed
Rises in the direction (arrow Y direction) perpendicular to the oscillation surface 5c by the shaft 2c, and the surface 6a of the substrate 6, the oscillation surface 5c, the side surface 6b of the substrate 6, the inner wall surface 5e, , That is, the separation distance is about 3 to
Stop at a position where it is about 5 mm.

In this state, the substrate 6 and the oscillation surface 5c
When the cleaning fluid 15 such as pure water is supplied from the liquid supply member 3a to the inner wall surface 5e in the direction of the arrow Xa,
The surface 6a and the oscillation surface 5c of the substrate 6 and the substrate 6
A liquid film of the cleaning fluid 15 is formed by the action of surface tension between the side surface 6b and the inner wall surface 6e of the protrusion 6d. When the table 2b is rotated in one direction by the shaft 2c, for example, and a voltage of a predetermined driving frequency is applied to the vibrator 4 from the oscillator (not shown), the liquid film of the cleaning fluid 15 is formed. The ultrasonic vibration from the vibrator 4 is transmitted to the substrate 6 via the vibrator 4.

The ultrasonic vibration oscillating from the vibrator 4 is
The vibration is transmitted in a direction perpendicular to the oscillation surface 5c, and the oscillation surface 5c having the same width as the vibrator 4 vibrates uniformly over the entire surface, and is evenly irradiated on the substrate 6 as an object to be cleaned. Thus, the surface 6a of the substrate 6 is cleaned.

The ultrasonic vibration generated from the vibrator 4 is applied to both sides of the oscillation surface 5c.
The light is reflected toward the inner wall surface 5e by the outer wall surface 5f which is a tapered surface having an angle of 45 degrees with respect to the inner wall surface 5e. Then, since the reflected ultrasonic vibration has the inner wall surface 5e having a curved surface equal to the radius of curvature of the substrate 6, the reflected ultrasonic vibration is directed substantially in the direction of the center of the substrate 6, that is, the side surface 6b of the substrate 6. It is configured to deflect in the direction.

Therefore, the side surface 6b can be cleaned simultaneously with the front surface 6a of the substrate 6. At this time, the concave portion 6c formed as a positioning mark on the semiconductor wafer or the like can be cleaned together, and the cleaning effect on the substrate 6 as the object to be cleaned is high.

When the cleaning is completed, the table 2b is lowered, and the substrate 6 as an object to be cleaned is pushed out onto the downstream roller 2a by the pressing means (not shown), and the substrate is moved to the next step. Conveyed.

The rotation direction of the table 2b can be set as appropriate, and the rotation direction may be changed sequentially. In addition, the rotation operation of the table 2b may be configured to repeat an operation of rotating by a predetermined angle and stopping, for example, corresponding to the concave portion 6c, in addition to the continuous rotation. It can be set as appropriate. In the second embodiment, the protruding portions 5d are formed as a pair. However, only one of them may be formed.

The shape of the protruding portion 5d may be any shape as long as it deflects a part of the traveling direction of the ultrasonic vibration and efficiently transmits the ultrasonic vibration from the inner wall surface 5e. The angle with respect to the oscillation surface 5c and the inner wall surface 5e can be appropriately changed.

In each of the embodiments, pure water is used as the cleaning fluid. However, various cleaning fluids can be used according to the purpose of cleaning and the material of the object to be cleaned.

In each embodiment, the waveguide 5
Is formed in a substantially rectangular parallelepiped shape, but various shapes such as a disk shape can be adopted according to the shape of the space to be installed.

[0085]

As described above, according to the ultrasonic excitation device of the present invention and the ultrasonic cleaning device provided with the same, the surface and the side surface of the object to be cleaned are simultaneously cleaned and the cleanliness of the object to be cleaned is improved. , And the device can be prevented from becoming complicated and large, and the amount of cleaning liquid can be reduced.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an ultrasonic cleaning apparatus as a first embodiment of the present invention.

FIG. 2 is a front view including a partial cross section of the ultrasonic cleaning apparatus shown in FIG.

FIG. 3 is an enlarged front view of a part of the ultrasonic cleaning apparatus shown in FIG.

FIG. 4 is a side view of the ultrasonic cleaning apparatus shown in FIG.

FIG. 5 is a perspective view including an enlarged view of a part of an ultrasonic cleaning apparatus as a second embodiment of the present invention.

FIG. 6 is a bottom view showing a state in which the ultrasonic cleaning apparatus shown in FIG. 5 cleans an object to be cleaned.

FIG. 7 is a sectional view of a conventional ultrasonic cleaning apparatus viewed from the front.

FIG. 8 is a bottom view of the conventional ultrasonic cleaning apparatus shown in FIG.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 ultrasonic excitation device 2 transport device (transport device) 2a roller 2b table 2c shaft 3 liquid supply device (liquid supply device) 3a liquid supply member 3b suction member 4 vibrator 4a, 4b electrode plate 5 waveguide 5a flange portion 5b Through hole 5c Oscillation surface 5d Projection 5e Inner wall surface 5f Outer wall surface 5g Ultrasonic wave propagation surface 6 Substrate (object to be cleaned) 6a Surface 6b Side surface 6c Concave portion 15 Cleaning fluid 20a Ultrasonic cleaning device (first embodiment) 20b Ultrasonic wave Cleaning device (second embodiment)

[Procedure amendment]

[Submission Date] March 3, 2000 (200.3.3)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Name of invention

[Correction method] Change

[Correction contents]

[Title of the Invention] Ultrasonic cleaning device

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] Claims

[Correction method] Change

[Correction contents]

[Claims]

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] 0001

[Correction method] Change

[Correction contents]

[0001]

The present invention relates to, for example, an ultrasonic cleaning device that used for washing, such as a semiconductor wafer or a glass substrate.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0015

[Correction method] Change

[Correction contents]

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and it is possible to simultaneously clean a surface and a side surface of an object to be cleaned, thereby improving the cleanliness of the object to be cleaned, and further increasing the complexity of the apparatus. It is an object of the present invention to provide an ultrasonic cleaning apparatus capable of avoiding upsizing and reducing the amount of cleaning liquid .

[Procedure amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0016

[Correction method] Change

[Correction contents]

[0016]

An ultrasonic cleaning apparatus according to the present invention comprises a vibrator for generating ultrasonic vibration and a vibrator connected to the vibrator.
And a waveguide for guiding the ultrasonic vibration to the cleaning fluid.
An ultrasonic excitation device and the vibrator of the waveguide,
For transporting along an oscillating surface opposite to a surface having
And the cleaning fluid between the oscillation surface and the object to be cleaned.
An ultrasonic cleaning device having a liquid supply means for supplying
The waveguide is a projection formed integrally with the oscillation surface.
The protrusion is provided facing the oscillation surface side.
And the method of transporting the object to be cleaned perpendicular to the oscillation surface.
An inner wall extending along the direction,
An outer wall deflecting toward the inner wall, and
The object is conveyed along the inner wall surface by the conveying means, and
The side of the object to be cleaned is cleaned .

[Procedure amendment 6]

[Document name to be amended] Statement

[Correction target item name] 0017

[Correction method] Change

[Correction contents]

[0017] The projecting portion may move the ultrasonic vibration.
The cross-sectional shape in the row direction is a right-angled isosceles triangle,
The outer wall has an angle with respect to the oscillation surface and the inner wall.
Have 45-degree faces.

[Procedure amendment 7]

[Document name to be amended] Statement

[Correction target item name] 0018

[Correction method] Change

[Correction contents]

Further, the ultrasonic vibration is applied to the outer wall surface.
Reflected in the direction perpendicular to the conveying direction of the object to be cleaned.
It deflects .

[Procedure amendment 8]

[Document name to be amended] Statement

[Correction target item name] 0019

[Correction method] Change

[Correction contents]

Further, the ultrasonic cleaning apparatus of the present invention can
A vibrator for generating vibration and the vibrator coupled to the supersonic
Excitation with Waveguide Leading Wave Vibration to Cleaning Fluid
An apparatus and a disc-shaped object to be cleaned are combined with the vibrator of the waveguide.
Can be transported in a direction perpendicular to the oscillation surface facing the surface
Between the oscillating surface and the object to be cleaned.
Ultrasonic cleaning having a liquid supply means for supplying the cleaning fluid
An apparatus, wherein the waveguide is integrally formed with the oscillation surface.
A protruding portion, wherein the protruding portion faces the oscillation surface side.
Perpendicular to the oscillation surface, and
An arc-shaped inner wall surface along the circumferential direction of the object;
And an outer wall for deflecting movement toward the inner wall side.
The object to be cleaned is rotated along the inner wall surface by the transport means.
The cleaning is performed by cleaning the side surface of the object to be cleaned.

[Procedure amendment 9]

[Document name to be amended] Statement

[Correction target item name] 0020

[Correction method] Change

[Correction contents]

Further, the outer wall surface includes the oscillating surface and the oscillating surface.
Each having an angle of 45 degrees to the inner wall surface
It is.

[Procedure amendment 10]

[Document name to be amended] Statement

[Correction target item name] 0021

[Correction method] Change

[Correction contents]

Further, the ultrasonic vibration is generated by the outer wall surface.
And is deflected toward the center of the object to be cleaned.
It is.

[Procedure amendment 11]

[Document name to be amended] Statement

[Correction target item name] 0022

[Correction method] Deleted

[Procedure amendment 12]

[Document name to be amended] Statement

[Correction target item name] 0023

[Correction method] Deleted

[Procedure amendment 13]

[Document name to be amended] Statement

[Correction target item name] 0060

[Correction method] Change

[Correction contents]

That is, the cross-sectional shape of the protruding portion 5d in the traveling direction of the ultrasonic vibration is a right-angled isosceles triangle, and the outer wall surface 5f is formed by the oscillation surface 5c and the inner wall surface 5c.
since it is in the plane that have a 45 degree angle with respect to e, ultrasonic vibration from the transducer 4 is transmitted in a direction perpendicular to the oscillation plane 5c is reflected by the outer wall surface 5f Then, it is deflected in the direction of the side surface 6b in the transport direction of the substrate 6 (the direction of the arrow X). Then, the cleaning fluid 15 in the form of a liquid film formed in the gap e is excited by the ultrasonic vibration transmitted from the inner wall surface 5e, and the side surface 6b of the substrate 6 can be cleaned. ing.

[Procedure amendment 14]

[Document name to be amended] Statement

[Correction target item name] 0063

[Correction method] Change

[Correction contents]

The waveguide 5 has the protruding portion 5d having a right isosceles triangular cross section in the traveling direction of the ultrasonic vibration, and the outer wall surface 5f of the protruding portion 5d is since it is in the plane you Yes <br/> an angle of 45 degrees with respect to the inner wall surface 5e, the side 6 of the substrate 6 the ultrasonic vibration from the transducer 4 by the outer wall surface 5f
The substrate 6 can be deflected in the direction b, and the surface 6a and the side surface 6b of the substrate 6 can be simultaneously cleaned to increase the cleanliness of the substrate 6 as an object to be cleaned. In addition, since the protruding portion 5d has a simple configuration integrally formed with the waveguide 5, it is easy to form, and a high cleaning effect can be obtained at low cost.

[Procedure amendment 15]

[Document name to be amended] Statement

[Correction target item name] 0070

[Correction method] Change

[Correction contents]

The ultrasonic excitation device 1 provided in the ultrasonic cleaning device 20b is arranged so that the ultrasonic vibrations generated from the vibrator 4 in the protruding portions 5d formed on both sides of the oscillation surface 5c of the waveguide 5 travel in the traveling direction. sectional shape in the can has become trapezoidal shape, that has an arc shape inner wall surface 5e along the circumferential direction of the substrate 6.

[Procedure amendment 16]

[Document name to be amended] Statement

[Correction target item name] 0078

[Correction method] Change

[Correction contents]

The ultrasonic vibration generated from the vibrator 4 is applied to both sides of the oscillation surface 5c.
The light is reflected toward the inner wall surface 5e by the outer wall surface 5f which is a tapered surface having an angle of 45 degrees with respect to the inner wall surface 5e. Then, the reflected ultrasonic vibrations substantially central direction direction before Symbol substrate 6, i.e.,
The substrate 6 is configured to deflect in the direction of the side surface 6b.

[Procedure amendment 17]

[Document name to be amended] Statement

[Correction target item name] 0085

[Correction method] Change

[Correction contents]

[0085]

As described above, according to the ultrasonic cleaning apparatus of the present invention , it is possible to simultaneously clean the surface and the side surface of the object to be cleaned, thereby improving the cleanliness of the object to be cleaned.
It is possible to avoid the complexity and size of the apparatus and to reduce the amount of cleaning liquid.

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Claims (8)

[Claims] 1. An ultrasonic excitation device comprising: a vibrator that generates ultrasonic vibration of about 200 kHz or more; and a waveguide that is coupled to the vibrator and guides the ultrasonic vibration to an external load. The waveguide includes a projection integrally formed on an oscillation surface facing the surface having the vibrator, and the projection is provided facing the oscillation surface side and is perpendicular to the oscillation surface. An ultrasonic excitation device comprising: an inner wall surface; and an outer wall surface that deflects the ultrasonic vibration toward the inner wall surface. 2. The ultrasonic excitation device according to claim 1, wherein the outer wall surface is a taper surface at 45 degrees with respect to the oscillation surface and the inner wall surface. 3. The ultrasonic excitation device according to claim 1, wherein the inner wall surface is an arc-shaped curved surface. 4. The waveguide has a dimension in the traveling direction of the ultrasonic vibration that is an integral multiple of a half wavelength of the ultrasonic vibration based on a sound velocity of a material of the waveguide, The acoustic impedances of the vibrator, the waveguide, and the external load satisfy Rma ₁ <Rma ₂ <Rma ₃ when Rma ₁ , Rma _2, and Rma ₃ respectively. The ultrasonic excitation device according to claim 3. 5. An ultrasonic cleaning apparatus comprising: a conveying unit that conveys an object to be cleaned; a liquid supply unit that supplies a cleaning fluid; and an ultrasonic excitation device that excites the cleaning fluid. The ultrasonic excitation device includes a vibrator that generates ultrasonic vibration of about 200 kHz or more, and a waveguide that is coupled to the vibrator and guides the ultrasonic vibration to the cleaning fluid. Comprises a projection integrally formed on an oscillation surface opposite to the surface having the vibrator, wherein the projection is provided facing the oscillation surface side and has an inner wall surface perpendicular to the oscillation surface. And an outer wall surface for deflecting the ultrasonic vibration toward the inner wall surface side. 6. The outer wall surface is a taper surface having an angle of 45 degrees with respect to the oscillating surface and the inner wall surface, respectively, and is approximately 3 degrees between the oscillating surface and the inner wall surface and the object to be cleaned.
The ultrasonic cleaning apparatus according to claim 5, wherein the ultrasonic cleaning apparatus has a gap of about 5 mm, and the liquid supply unit supplies the cleaning fluid into the gap. 7. The ultrasonic cleaning apparatus according to claim 5, wherein the transporting apparatus transports the object to be cleaned along the inner wall surface. 8. The ultrasonic cleaning apparatus according to claim 5, wherein the inner wall surface is a curved surface equal to a radius of curvature of the object to be cleaned.